Net core windows server hosting bundle

Windows desktop operating systems¶

Navigate to Control Panel > Programs > Programs and Features > Turn Windows features on or off (left side of the screen). Open the group for Internet Information Services and Web Management Tools. Check the box for IIS Management Console. Check the box for World Wide Web Services. Accept the default features for World Wide Web Services or customize the IIS features to suit your needs.

Windows Server operating systems¶

For server operating systems, use the Add Roles and Features Wizard via the Manage menu or the link in Server Manager. On the Server Roles step, check the box for Web Server (IIS).

On the Role services step, select the IIS role services you desire or accept the default role services provided.

Proceed through the Confirmation step to enable the web server role and services.

Enabling the IISIntegration components¶

Include a dependency on the Microsoft.AspNetCore.Server.IISIntegration package in the application dependencies. Incorporate IIS Integration middleware into the application by adding the .UseIISIntegration() extension method to WebHostBuilder().

var host = new WebHostBuilder()
  .UseKestrel()
  .UseContentRoot(Directory.GetCurrentDirectory())
  .UseIISIntegration()
  .UseStartup<Startup>()
  .Build();

Note that code calling .UseIISIntegration() does not affect code portability.

Setting IISOptions for the IISIntegration service¶

To configure IISIntegration service options, include a service configuration for IISOptions in ConfigureServices.

services.Configure<IISOptions>(options => {
  ...
});

Warning

.NET Core applications are hosted via a reverse-proxy between IIS and the Kestrel server. In order to create the reverse-proxy, the web.config file must be present at the content root path (typically the app base path) of the deployed application, which is the website physical path provided to IIS.

Sensitive files exist on the app’s physical path, including subfolders, such as my_application.runtimeconfig.json, my_application.xml (XML Documentation comments), and my_application.deps.json. The web.config file is required to create the reverse proxy to Kestrel, which prevents IIS from serving these and other sensitive files. Therefore, it is important that the web.config file is never accidently renamed or removed from the deployment.

Note

If you change the default identity of the application pool from ApplicationPoolIdentity, verify the new identity has the required permissions to access the application’s assets and database.

Warning

Data Protection is used by various ASP.NET middlewares, including those used in authentication. Even if you do not specifically call any Data Protection APIs from your own code you should configure Data Protection with the deployment script or in your own code. If you do not configure data protection when using IIS by default the keys will be held in memory and discarded when your application closes or restarts. This will then, for example, invalidate any cookies written by the cookie authentication and users will have to login again.

Installer unable to obtain VC++ Redistributable¶

• Installer Exception: Installation of the .NET Core Windows Server Hosting Bundle fails with 0x80070002 — The system cannot find the file specified.

Troubleshooting:

• If the server does not have Internet access while installing the server hosting bundle, this exception will ensue when the installer is prevented from obtaining the Microsoft Visual C++ 2015 Redistributable (x64) packages online. You may obtain an installer for the packages from the Microsoft Download Center.

Platform conflicts with RID¶

• Browser: HTTP Error 502.5 — Process Failure
• Application Log:
  — Application Error: Faulting module: KERNELBASE.dll Exception code: 0xe0434352 Faulting module path: C:\WINDOWS\system32\KERNELBASE.dll
  — IIS AspNetCore Module: Failed to start process with commandline ‘“dotnet” .\my_application.dll’ (portable app) or ‘“PATH\my_application.exe”’ (self-contained app), ErrorCode = ‘0x80004005’.
• ASP.NET Core Module Log: Unhandled Exception: System.BadImageFormatException: Could not load file or assembly ‘teststandalone.dll’ or one of its dependencies. An attempt was made to load a program with an incorrect format.

Troubleshooting:

• If you published a self-contained application, confirm that you didn’t set a platform in buildOptions of project.json that conflicts with the publishing RID. For example, do not specify a platform of x86 and publish with an RID of win81-x64 (dotnet publish -c Release -r win81-x64). The project will publish without warning or error but fail with the above logged exceptions on the server.

URI endpoint wrong or stopped website¶

• Browser: ERR_CONNECTION_REFUSED
• Application Log: No entry
• ASP.NET Core Module Log: Log file not created

Troubleshooting:

• Confirm you are using the correct URI endpoint for the application. Check your bindings.
• Confirm that the IIS website is not in the Stopped state.

CoreWebEngine or W3SVC server features disabled¶

• OS Exception: The IIS 7.0 CoreWebEngine and W3SVC features must be installed to use the Microsoft HTTP Platform Handler 1.x.

Troubleshooting:

• Confirm that you have enabled the proper server role and features. See IIS Configuration.

Incorrect website physical path or application missing¶

• Browser: 403 Forbidden: Access is denied –OR– 403.14 Forbidden: The Web server is configured to not list the contents of this directory.
• Application Log: No entry
• ASP.NET Core Module Log: Log file not created

Troubleshooting:

• Check the IIS website Basic Settings and the physical application assets folder. Confirm that the application is in the folder at the IIS website Physical path.

Incorrect server role, module not installed, or incorrect permissions¶

• Browser: 500.19 Internal Server Error: The requested page cannot be accessed because the related configuration data for the page is invalid.
• Application Log: No entry
• ASP.NET Core Module Log: Log file not created

Troubleshooting:

• Confirm that you have enabled the proper server role. See IIS Configuration.
• Check Programs & Features and confirm that the Microsoft ASP.NET Core Module has been installed. If the Microsoft ASP.NET Core Module is not present in the list of installed programs, install the module. See IIS Configuration.
• Make sure that the Application Pool Process Model Identity is either set to ApplicationPoolIdentity; or if a custom identity is in use, confirm the identity has the correct permissions to access the application’s assets folder.

Hosting bundle not installed or server not restarted¶

• Browser: 502.3 Bad Gateway: There was a connection error while trying to route the request.
• Application Log: Process ‘0’ failed to start. Port = PORT, Error Code = ‘-2147024894’.
• ASP.NET Core Module Log: Log file created but empty

Troubleshooting:

• You may have deployed a portable application without installing .NET Core on the server. If you are attempting to deploy a portable application and have not installed .NET Core, run the .NET Core Windows Server Hosting Bundle Installer on the server. See Install the .NET Core Windows Server Hosting Bundle.
• You may have deployed a portable application and installed .NET Core without restarting IIS. Either restart the server or restart IIS by executing net stop was /y followed by net start w3svc from the command-line.

Incorrect processPath, missing PATH variable, or dotnet.exe access violation¶

• Browser: HTTP Error 502.5 — Process Failure
• Application Log: Failed to start process with commandline ‘“dotnet” .\my_application.dll’ (portable app) or ‘”.\my_application_Foo.exe”’ (self-contained app), ErrorCode = ‘0x80070002’.
• ASP.NET Core Module Log: Log file created but empty

Troubleshooting:

• Check the processPath attribute on the <aspNetCore> element in web.config to confirm that it is dotnet for a portable application or .\my_application.exe for a self-contained application.
• For a portable application, dotnet.exe might not be accessible via the PATH settings. Confirm that C:\Program Files\dotnet\ exists in the System PATH settings.
• For a portable application, dotnet.exe might not be accessible for the user identity of the Application Pool. Confirm that the AppPool user identity has access to the C:\Program Files\dotnet directory.
• You may have deployed a portable application and installed .NET Core without restarting IIS. Either restart the server or restart IIS by executing net stop was /y followed by net start w3svc from the command-line.

Incorrect arguments of <aspNetCore> element¶

• Browser: HTTP Error 502.5 — Process Failure
• Application Log: Failed to start process with commandline ‘“dotnet” .\my_application_Foo.dll’, ErrorCode = ‘0x80004005’.
• ASP.NET Core Module Log: The application to execute does not exist: ‘PATH\my_application_Foo.dll’

Troubleshooting:

• Examine the arguments attribute on the <aspNetCore> element in web.config to confirm that it is either (a) .\my_applciation.dll for a portable application; or (b) not present, an empty string (arguments=”“), or a list of your application’s arguments (arguments=”arg1, arg2, …”) for a self-contained application.

Missing .NET Framework version¶

• Browser: 502.3 Bad Gateway: There was a connection error while trying to route the request.
• Application Log: Failed to start process with commandline ‘[IIS_WEBSITE_PHYSICAL_PATH] ‘, Error Code = ‘0x80004005’.
• ASP.NET Core Module Log: Missing method, file, or assembly exception. The method, file, or assembly specified in the exception is a .NET Framework method, file, or assembly.

Troubleshooting:

• Install the .NET Framework version missing from the server.

Stopped Application Pool¶

• Browser: 503 Service Unavailable
• Application Log: No entry
• ASP.NET Core Module Log: Log file not created

Troubleshooting

• Confirm that the Application Pool is not in the Stopped state.

IIS Integration middleware not implemented or .UseUrls() after .UseIISIntegration()¶

• Browser: HTTP Error 502.5 — Process Failure
• Application Log: Process was created with commandline ‘“dotnet” .\my_application.dll’ (portable app) or ‘”.\my_application.exe”’ (self-contained app) but either crashed or did not reponse within given time or did not listen on the given port ‘PORT’, ErrorCode = ‘0x800705b4’
• ASP.NET Core Module Log: Log file created and shows normal operation.

Troubleshooting

• Confirm that you have correctly referenced the IIS Integration middleware by calling the .UseIISIntegration() method of the application’s WebHostBuilder().
• If you are using the .UseUrls() extension method when self-hosting with Kestrel, confirm that it is positioned before the .UseIISIntegration() extension method on WebHostBuilder(). .UseIISIntegration() must set the Url for the reverse-proxy when running Kestrel behind IIS and not have its value overridden by .UseUrls().

Sub-application includes a <handlers> section¶

• Browser: HTTP Error 500.19 — Internal Server Error
• Application Log: No entry
• ASP.NET Core Module Log: Log file created and shows normal operation for the root application. Log file not created for the sub-application.

Troubleshooting

• Confirm that the sub-application’s web.config file doesn’t include a <handlers> section.

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